The presently disclosed subject matter relates to an apparatus for determining the respiratory condition of the subject in order to examine or monitor sleep respiratory disorder.
As one of apnea/hypopnea conditions occurring during sleep, there is obstructive apnea/hypopnea in which a respiratory effort is continued in an airway obstruction condition. In other words, when the respiratory effort of the subject is detected, it is possible to determine that sleep respiratory disorder occurs. A respiratory effort is recognized by measuring the airway pressure. There is an apparatus for determining the respiratory condition in which a sensor catheter is inserted into the esophagus of the subject to measure the airway pressure (for example, see JP-T-2010-540118).
In examination or monitoring of sleep respiratory disorder, it is required to perform a long-term overnight measurement. A long-term measurement in a state where catheter is inserted into the esophagus inevitably imposes significant botheration and burden on the subject. Under such a situation, the subject cannot sleep, and it is difficult to adequately perform a sleep test. For a person who performs diagnosis, on the other hand, a work of visually determining the respiratory condition of the subject from an enormous number of measurement signal waveforms which have been measured overnight causes a very large burden. In the case where the determination is performed based on visual observation, moreover, it is difficult to eliminate differences in determination results due to the subjectivity and experience of the observer.